The Biostatistics and Data Management Core has been re-designed to provide a high level of statistical and data management support to each of the Program Project's three studies. This core component is affiliated with the Center for the Biopsychosocial Study of AIDS, and makes use of the extensive system development undertaken by that Center over the past five years. The Center is linked with the Behavioral Medicine Research Center (BMRC) in Jackson Medical Towers on the Medical School Campus and with the Behavioral Medicine Building (BMRB) on the Coral Gables Campus through a high speed fiber optics communication network. The specific aims of the Biostatistics and Data Management Core fall into two broad categories. The first category is designed to provide centralized biostatistical and methodological assistance to each of the Project's studies. This assistance includes: (1) supervising all aspects of data analysis; (2) consulting on methodological issues associated with data analysis or data quality control; and, (3) developing new and creative approaches to handling statistical issues and problems. The second category is designed to provide an integrated data management structure for the three Project studies. This structure includes: (1) designing and programming screens for data entry; (2) designing and programming procedures to perform data verification through range checks; (3) designing and programming procedures to properly flag a variety of missing data types; (4) designing and programming routine reports for quality assurance and subject tracking; and, (5) designing procedures to facilitate the transfer of data between the data management system, the mainframe computer systems on the Coral Gables Campus (e.g., for analyses with SAS, BMDP, SPSS, or other specific analysis systems), and individual micro systems (e.g., for analyses with SAS-PC, SPSS-PC, SYSTAT or LIMDEP).